The leaders of the United States and North Korea could meet face-to-face by May this year.
A South Korean delegation that went to Washington last night passed on a message from Pyongyang to Donald Trump.
Kim Jong Un is apparently ready to suspend nuclear missile tests and come to the negotiating table.
President Trump had previously threatened "fire and fury" in response to threats from North Korea. Mr Trump also referred to the North Korean leader as "Little Rocket Man".
But on Friday, he tweeted: "Kim Jong Un talked about denuclearisation with the South Korean representatives, not just a freeze.
"Also, no missile testing by North Korea during this period of time. Great progress being made but sanctions will remain until an agreement is reached. Meeting being planned!".
Kim Jong Un talked about denuclearization with the South Korean Representatives, not just a freeze. Also, no missile testing by North Korea during this period of time. Great progress being made but sanctions will remain until an agreement is reached. Meeting being planned!
— Donald J. Trump (@realDonaldTrump) March 9, 2018
It comes after South Korea's national security adviser Chung Eui Yong announced at the White House Mr Kim's desire to meet with Mr Trump following talks in Pyongyang on Monday.
He (Mr Kim) expressed his eagerness to meet President Trump as soon as possible," said the South Korean official. "President Trump appreciated the briefing and said he would meet Kim Jong Un by May to achieve permanent denuclearisation."